Within, the Enemy
by AstroGirl
Summary: An AU branching off from the TV movie, in which the Master succeeds in taking over the Doctor's body.


**Within, the Enemy**

**by AstroGirl**

It works. It _works_. A surge of energy crashes through him, both similar to and indescribably different from the transformative rush of regeneration, and when it subsides he is looking at the world through his enemy's eyes.

The chains unlock, as he has rigged them to, and he carefully removes the apparatus from his head. Around him, the room is littered with corpses: the surgeon; the boy; the now-useless form that once was Bruce, lying crumpled and still in full Time Lord regalia. Later, he will tidy up here, reclaim the clothing, but for the moment, the only body he cares about is the Doctor's body. _His_ body, now.

Such sweet relief it is to inhabit a proper body again at last. He can still feel the energy of recent regeneration tingling through its cells -- _his_ cells -- and hear two hearts thumping healthy drum-beats in his chest. He is _alive_, flush with stored oxygen and stored lives, and at long last, he can no longer feel the pressure of his mind straining and pushing against the limits of a brain too small to hold it. He had almost forgotten what it was like not to spend every moment compressing his consciousness by the sheer force of his will. The sensation is little short of bliss, but it is far from his _true_ triumph.

He must find a mirror. He must look in at himself, looking out from the Doctor's face.

He expects that he will have to search for one, here in the chaotic labyrinth of the Doctor's TARDIS, but he finds it easily, in the first room he bothers to check.

Unclothed, he stands before the polished glass and maps the contours of this warm, new flesh out with his hands. It is a good body: healthy, well-built, young. As for the face... He cups his cheek with one hand and considers. There is a certain innocent prettiness to the features that really isn't _him_, though lopping off those ridiculous curls and perhaps cultivating a beard will no doubt do much to bring it into alignment with his self-image.

The eyes, however, are his already: hard and brittle and full of hate. They are the eyes of a killer, and the sight of them in a face he still thinks of as the Doctor's excites him even more than he'd expected.

He stands for a long, long time before the mirror, and he comes back to it again and again. But he never does cut the hair, or grow the beard.

* * *

It is almost a pity, really that this regeneration is so new. How much easier -- how much more _satisfying_ -- his extended revenge would be if he could appear to the Doctor's pitiful human friends wearing a face they have known and loved. Still, it is not difficult to be convincing in the part, not when he possesses the Doctor's TARDIS. Not when he has spent lifetimes intimately studying the role.

Certainly Mrs. Josephine Jones -- an obvious first victim, but in his estimation an apt one -- shows little doubt about his identity once her initial surprise has faded. How delightful it is to see the innocent smile on her annoying, insipid face as the Doctor's characteristic inane babble tumbles smoothly from his mouth and to know that he possesses the power to turn that expression instantly to one of shock and fear. He is not sure which he will relish more, the betrayal she will feel when her beloved Doctor turns against her, or the horror when she realizes that the Doctor is no longer the Doctor at all.

And yet, when the crowning moment is at hand, when his newly refashioned TCE lies inches from her face and his sudden, cruel laughter ignites the first flash of recognition in her eyes, he finds himself suddenly unable to continue. Something inside him is stirring, rising up from underneath the conscious layers of his mind. Something full of anger, and sorrow, and determination. His hand begins to shake, the TCE oscillating wildly before Jo's wide, startled eyes until it escapes his grip entirely and falls clattering to the floor.

Nausea overtakes him, as if what he nearly did has inexplicably sickened him, and as he bends over, gasping for air and calmness, the girl runs off screaming for help.

He makes his exit in the TARDIS before she can return, no doubt with UNIT in tow. It is a calculated, prudent withdrawal, and very much his own decision. And yet, he cannot help but be aware of that restless, buried presence and its intense desire not to see the Brigadier again like this.

* * *

He stands before the mirror once again.

"So," he whispers to his reflection, "you are still here." The Master raises a hand to his head, fingers sliding beneath the tangled curls and across the skin of his scalp, as if they could reach through bone and brain to caress whatever might remain of the Doctor's mind.

This is better than he had hoped, a more perfect revenge than even his brilliant, devious mind could ever have invented. To have stolen not only the Doctor's body, but his soul, to know that he holds the Doctor inside him, trapped and helpless... The Master's pulses race at the thought.

"Oh, Doctor. We will wreak such beautiful destruction together, you and I." With one hand, he gently touches the mirror image's cheek, as the other, still threaded through his hair, clenches into a fist and yanks.

The Master throws back his head and laughs. So does the image in the mirror, exposing its vulnerable throat.

* * *

He begins by conquering a planet. Logistically, it's almost embarrassingly easy; the inhabitants are natural pacifists who have spent the last ten millennia gazing philosophically at their navels, cultivating the most impractical of sciences, and composing endless, complex poems in praise of their world, each other, and the universe in general. It is, in other words, exactly the sort of place guaranteed to arouse the Doctor's most disgustingly protective instincts. And therein lies both the appeal and the difficulty.

Now that he is aware of the existence of the Doctor's mind lurking beneath his own, he is entirely capable of bringing his will to bear upon it. Tighten his control, and the Doctor's thoughts are crushed into darkness, quiescent and contained. Loosen a little, and he can feel that stirring again, that... _Doctorness_. The brain he now inhabits begins to recognize its proper occupant, and the Master finds thoughts and reactions that are not his own insinuating themselves into the once-inviolate pathways of his mind.

A Doctor too suppressed is incapable of perceiving his actions, rendering them meaningless. But one given too much room in which to think leaves the Master incapable of enjoying them. It is an interesting conundrum, and he dedicates himself wholeheartedly to exploring it.

He has slaves brought to him, one by one, and subjects them to tortures subtle and gross. To the sound of whimpers and screams, he constricts his will and relaxes it, constricts and relaxes, as he attempts to find the perfect balance. Detached disinterest becomes glee at the Doctor's pain, becomes anger and revulsion, becomes a satisfying re-assumption of power, becomes detachment and boredom again, as the cycle repeats.

Eventually it becomes clear to him that his sought-for perfect balance does not exist, that there is no safe compromise between giving the Doctor too much power over him and suffering the Doctor's absence. And yet, caught in fascinating cycles of pleasure and pain, he cannot quite bring himself to stop.

Consumed as he is with this experiment to the exclusion of all else, it takes him by surprise when his subjects, less pacifist than they first appeared, rise up and evict him from their world. More disturbing than the loss of his conquest, though, is the way his brain flicks back and forth between anger and happiness, faster and faster, until he can almost feel both responses at once.

As he enters the Vortex, he clamps down hard, until he no longer feels anything at all.

* * *

The emptiness in his mind is deafening, an echo chamber for the faint, distant drums he has always imagined he could hear beating out the passing moments of his life. Clearly he needs a distraction, something with which to fill his thoughts and his days.

Overhauling this doddering wreck of a TARDIS is something he should have done as soon as he acquired it, and it certainly makes for an adequately absorbing task. The Doctor's maintenance schedule has obviously been haphazard, his repairs makeshift, his modifications brilliant but insane. Which means that there is a gratifyingly large amount of work to be done to restore it to a state that will satisfy the Master's sense of order, but also that plunging into the time capsule's circuitry is disturbingly like entering the Doctor's mind.

Half-absorbed in the workings of the Doctor's psyche already, thoroughly engrossed in the task at hand, it becomes far too easy to yield to the temptation to relax his hold on the Doctor's thoughts, just for a moment, and let the knowledge of where he's cross-circuited the helmic regulator to bubble up into the Master's awareness. And, that having proved successful with no ill effect, it is even easier to do it again, just a little more, and find out what in Rassilon's name that ungainly addition to the temporal override circuit was meant to accomplish. And then again, to help him trace out the non-standard alpha-mapping of the phase regulation system.

By the time the project is nearly complete, it feels almost as if the two of them are working together, the way they did regularly in times long past. It fills him with a surprising sense of pleasure.

* * *

Perhaps, he thinks, touching the mirror again, it is an even better revenge to force the Doctor truly to become one with him, joined forever to a man he once rejected with such undeserved scorn and such supercilious contempt. The thought has an undeniable appeal, though he cannot help but wonder whether it has as much to do with a fear of returning to emptiness as it does with genuine thoughts of vengeance.

He closes his eyes and concentrates on the feel of the Doctor's mind where it presses against his, the shape and texture of the Doctor's thoughts still so familiar from so many lifetimes ago. He can sense the Doctor's boundaries blurring into his at the edges, a subtle, insidious colonization that must have occurred as he foolishly dulled his mind with busywork and fatuous memories of comradeship.

Somewhere inside him, the Doctor still _feels_. Which, in truth, is all he ever did. Always so full of pointless, weak emotions, never harnessed to useful effect and never expended on the deserving. And now he feels trapped. That much is clear, that familiar frustrated pain of having what is rightfully yours stripped from you, of finding yourself imprisoned at another's mercy. The Master has felt that at his hands often enough. He tries to take the appropriate glee in the Doctor's well-earned suffering, but the chuckle that emerges from his throat is limp and rings unconvincingly in his ears.

There is something else, too, he realizes, behind the pain and fear in the Doctor's mind. Something... hopeful? Really, the apparent impossibility of ever entirely crushing the man's spirit is maddening, and yet when he laughs at _that _thought, it comes forth sounding genuine and warm.

And more, beyond and through everything else, welling up from somewhere deep within the Doctor's psyche and bleeding softly through into his own, he senses something else entirely, some emotion he has difficulty recognizing for a moment, until some stray piece of Doctorness clicks inside him and he realizes with a jolt that it is _pity_.

Pity. _This_ is the thing about the Doctor that has always enraged him most, this arrogant presumption that assumes that he _deserves_ such sentiments as pity and forgiveness, and that the Doctor, of all people, possesses the right to bestow them. He has never needed the Doctor's pity, never _wanted_ the Doctor's pity. He has conquered galaxies in vain attempts to turn that pity to respect, and now to find it _inside_ him! The realization is sickening, mortifying. And yet..

And yet from this angle, pity feels rather different than he has always imagined it. Less like arrogance, and more like... What is it called, when one cares about someone enough to feel unhappy when they go wrong? Disappointment, he would have said, and contempt for their weakness, and anger at the loss of whatever good you might have got from them under better circumstances. Not this, whatever this emotion is.

He always assumed that his feelings towards the Doctor were mutual, their situation symmetric, and that if in the Doctor's case there were additional complications that went by names such as "compassion," those were nothing more than euphemisms for sentimental weakness. But the Doctor's pity as it rises through him is neither sentimental nor weak, not as the Master understands the terms. Instead it is sad and strong, and it frightens him badly.

Still resting against the mirror, his hand becomes a fist. He pushes the Doctor down, shoves him, bears upon him with the full force of his will, but the Doctor is too anchored now, too entwined, and with a sudden visceral shock, the Master realizes that he can no longer suppress him without ripping bloody chunks from the core of his own mind.

For a wild, panicked moment, he considers it anyway, but apparently the Doctor has at last discovered the one thing the Master cannot bring himself do in the name of revenge. So, then. This is it. His final defeat. He slumps down against the mirror, his eyes still closed, and his breath comes in heaving, choking gasps until his respiratory bypass system takes over and cuts them off.

_You know_, a soft voice sounds, finally, in his head. _You could try simply _talking_ to me, for once._

He opens his eyes, slowly, and stares into the mirror. With great weariness, but no very great surprise, he notes that the person looking back at him no longer has a killer's eyes.

And so, in the end, he talks.

* * *

_All across the universe, there are stories of a Time Lord, a traveler in time and space... He wanders alone, but he never seems lonely, as if his own company and that of the universe through which he moves are enough for him. His anger, they say, is as sharp as his wit, and as ready, but whenever he is moved to kill, some inner mercy invariably stays his hand. He revels in destruction, but only of the corrupt and the cruel, and he has liberated the oppressed of a thousand worlds. Those he frees he stays, for a time, to lead, but always when new order and prosperity are restored, or when the people come to worship him too much, restlessness strikes him and he vanishes, leaving their lives and destinies once more in their hands._

_Legends say that once he had an enemy with whom he battled across the centuries and across the stars, until they met in one final, climactic conflict. But on the nature of that conflict, or its outcome, no two stories ever seem to agree._

_From time to time, an especially bold or inquisitive being will ask him if these tales are true, and, if there was indeed a final battle after which they fought no more, which of them is it who ultimately won?_

_But if he will reply at all, the only answer he gives is "I don't know."_


End file.
